So, of all the things you may do wrong, "Leaving food and water out is the single biggest mistake," said entomologist Frederique de Lame, of Combat brand's research and development department.

Anti-ant things you can do indoors:

Ants come in through tiny gaps between the wall and utility lines, around windows, and other small holes and cracks. A bit of caulk around these areas will help keep them out.

Keep vegetation about 1 foot away from the home, and don't put mulch near the building. Ants can climb bushes and trees to make their way into your home; mulch makes an attractive nesting spot for them.

Fix water leaks, and insulate cold pipes and appliances to avoid condensation. The most important thing in an ant's life is water, and they'll readily enter your home to get it. Don't overwater houseplants; empty a full tray under the plant pot.

Leave pet food out only at feeding time; store it in plastic airtight containers.

If ants do get inside, sprays are temporarily effective. But for a long-term solution, put insecticide baits or gels where you see or have seen ants, for them to take back and wipe out their entire colony.

Insect species that bug us outdoors call for active discouragement, too. Bob Young, division service manager of pest-control company Terminix, repeated the familiar warning: Don't feed the little monsters.

"One of the worst things you can do is to leave food out and unattended," he said. "Even leaving behind traces of spilled drinks and dropped crumbs is an open invitation for insects."

Flies are more than a nuisance, since they spread disease. Make them unwelcome by using fans to make a light breeze across a table (flies are not strong flyers); serve food in containers with removable lids; put trash receptacles as far away from you as possible.

Mosquitoes are bloodthirsty pests and transmit the potentially dangerous West Nile virus. To avoid attracting them, remove scented candles from the area (mosquitoes and other pests might mistake the scent for fruit or flowers); empty birdbaths and children's pools at least once a week to eliminate breeding grounds.

Strings of colored bulbs or lanterns look festive but attract insects. Keep the mood by lighting the eating, cooking and social areas from a distance.

An important tip about lighting: "Homeowners should also remember to change their white outdoor lighting to yellow during the warmer months," Young said. This is because insects can see certain colors in the spectrum better than others, and white light is a color that attracts the flying and crawling insects that are so active in spring and summer.

While yellow lights don't repel bugs, they don't attract as many because the bugs can't see the yellow light as well.